Diagnostic Test

CHECK FOR ENGINE COOLING DTCS
1. With the scan tool, read all DTCs and record on the repair order.
  Are any engine cooling or Active Grille Shutter (AGS) DTCs set?
  
  Yes
  - Perform the applicable PCM DTC procedure(s). Refer to 3.6L - DIAGNOSTIC CODE INDEX .
  No
  - Go To 2
CHECK FOR OTHER TRANSMISSION DTCS
NOTE:
Before performing this Diagnostic Test, be certain that there are no problems that could cause the Transmission to overheat. Check for restricted transmission oil cooler and lines, air flow restrictions, and low transmission fluid. Towing loads weighing more than the recommended towing capacity could cause excessively high transmission temperatures.
1. With the scan tool, read all DTCs.
  Are there any other TCM DTCs set?
  
  Yes
  - Perform the other TCM DTC procedure(s). Refer to 948TE/9HP48 - DIAGNOSTIC CODE INDEX .
  No
  - Go To 3
CHECK FOR AN ACTIVE DTC
1. Record the Event Data and Environmental Data.
2. With the scan tool, erase DTCs.
3. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
4. With the scan tool, read TCM DTCs.
  Did the DTC return?
  
  Yes
  - Go To 4
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE (T54) TRANSMISSION TEMPERATURE SENSOR SIGNAL AND THE (T820) TRANSMISSION TEMPERATURE SENSOR GROUND CIRCUITS FOR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the TCM harness connector.
3. Disconnect the Transmission Assembly harness connector.
4. Connect a jumper wire between the (T54) Transmission Temperature Signal circuit and the (T820) Sensor Ground circuit at the Transmission Assembly harness connector.
5. Measure resistance between (T54) Transmission Temperature Signal circuit and the (T820) Sensor Ground circuit at the TCM harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (T54) Transmission Temperature Signal circuit or the (T820) Sensor Ground circuit for an open or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .

VERIFY TRANSMISSION TEMPERATURE SENSOR RESISTANCE / TEMPERATURE CORRELATION

Measure the resistance between (T54) Transmission Temperature Signal terminal and (T820) Sensor Ground terminal at the Transmission Assembly harness connector (Transmission side).

TEMPERATURE vs RESISTANCE
TEMPERATURE	RESISTANCE
-30°C (-22°F)	37, 400 - 50, 600 Ohms
10°C (50°F)	5, 810 - 7, 100 Ohms
110°C (230°F)	231 - 263 Ohms
145°C (293°F)	105 - 117 Ohms

Using the chart above, compare the Temperature Sensor temperature to the correlating resistance value.

Is the resistance within the specified range when the sensor is at the given temperature?

Yes

Go To 6

Replace the Transmission Internal Wiring Harness in accordance with the Service Information. Refer to HARNESS, INTERNAL WIRE, REMOVAL .
Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .

CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all TCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the Transmission Assembly harness connector.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Connect all TCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read TCM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Transmission Control Module (TCM) in accordance with the Service information. Refer to MODULE, TRANSMISSION CONTROL (TCM), REMOVAL .
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
  No
  - Repair the poor connections.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .